This invention relates to a display device for displaying input data such as a trend graph which is sampled at constant period, and more particularly to a display device having edition function capable for displaying a plurality of data areas in which some of the data is enlarged and/or reduced.
In a conventional display device, for example, as disclosed in the J-P-A 61-290485, a part of data is enlarged and is displayed on the whole display area. However, according to the conventional display device, an enlarged and a reduced data areas cannot be mixed and displayed. Furthermore, data do not continue between an enlarged area and a non-enlarged area.
Namely, according to the conventional display device, a predetermined area of a graph is reduced or enlarged in order to easily observe the graph. However, display edition function for easily observing a relationship between the reduced or enlarged area and whole data is not considered in the conventional device, so that an operator cannot easily obtain regulated data from one graph.